There is a need for carrying out drying of objects to be dried quickly. In a manufacturing process of lithium-ion batteries, moisture often adheres to electrodes in particular. When electrolytic solutions are injected to the electrodes to which the moisture adheres, the electrolytic solutions react with the moisture. This results in deterioration of the electrodes.
When a manufacturing environment is controlled constantly at a dew-point temperature (dew-point temperature: −25 degrees Celsius or less), the moisture does not adhere to the electrodes. However, in reality, it is not possible to control the manufacturing environment in such a manner. It is more realistic that the electrodes are dried to remove the moisture just before the electrolytic solutions are injected thereto.
According to WO01/095682, a pressure inside a chamber in which the object to be dried is provided is reduced. The pressure reduction allows a boiling point to decrease. As a result of this, the moisture is evaporated with ease. Thus, a drying time is shortened.